Mainkai, Riverside promenade in Frankfurt's Old Town, Germany

Mainkai is a paved riverside promenade along the Main River in central Frankfurt, running between the Old Town and neighboring districts. On one side flows the river, with views of old bridges and glass towers beyond; on the other, benches, small cafés, and food stands line the walkway.

Mainkai grew from a medieval landing and fortified quay on the right bank of the Main; archaeological finds at the Historisches Museum site show a quay wall from the late Middle Ages. From the 12th century the Mainz market boat left the Fahrtor daily at 10 a.m., taking seven to nine hours downstream. The bank between Metzgertor and Leonhardstor remained Frankfurt's main harbour until the end of the 19th century, handling timber floated from the upper Main and wine from Franconia and the Rheingau. The street itself was created from 1826 by filling and widening the bank.

The Mainkai's name comes from its use as a quay (Kai) on the Main. Since the Middle Ages, the bank between the Metzgertor and Leonhardstor gates was Frankfurt's main harbor, where wood floated downstream was unloaded and wine from Franconia and the Rheingau was stored. From the 14th century, the Mainzer Marktschiff left the Fahrtor daily at 10 a.m. for Mainz, carrying passengers, goods and post; the trip took seven to nine hours.

Mainkai is easy to reach on foot from Frankfurt's Old Town and Römerberg square, both just a short walk away. Comfortable shoes are a good idea, as parts of the path have uneven cobblestones, and some sections can get crowded on warm afternoons.

Some of the benches along Mainkai are tucked under trees and positioned so that they face the cathedral and the old bridges at the same time, a combination that is easy to miss if you stay on the main path. Early mornings are when the quay feels most different, with the water still and almost no one around.